Modular electrical plugs and sockets for professional use are known. However, standardized plugs and sockets are generally too big to make a space efficient modular solution for domestic use. For example, using a device connector socket/plug, such as the IEC C19/C20, would make the system become too big to be comparable with non-modular socket strips.
Using an industrial plug and socket, such as the standard, flat 3 pole connector, would also make the system too big and this type of connector is usually not suitable for transferring bending loads from one module to the next.
A industrial connector would also not be suitable either due its locking mechanism which requires a rotating movement to engage and for a modular electrical system it's most beneficial for the user to have an axial motion for connecting one module to the other.
Furthermore, the above mentioned connectors have no shutter protecting the current carrying connector sockets.
There are smaller connectors than the ones mentioned above but they are not intended for such high loads as 250 V and 16 A which is necessary for such a module system to be safe for domestic use.